The invention relates to a circuit arrangement for the variable interconnection of energy sources and energy consumers.
Presently, decentralized energy generation units, for example photovoltaic systems, are in widespread use in commercial and private buildings. In addition, it should be assumed that in future rechargeable batteries of electrically operated vehicles will be connected to the grid in greater quantities in the same buildings. Said rechargeable batteries are both an energy sink and an energy source. Further devices which may become more prevalent are wind generators and water-based generators, for example.
Typically, all such devices are nowadays constructed with a respective dedicated AC/DC connection. A first disadvantage of this is that there is a certain degree of redundancy of the power electronics components, which has a negative impact on costs and installation space. Another disadvantage is that it is difficult to monitor the energy flow between the supply grid and the individual devices available.
EP 2317623 A1 has disclosed a so-called “demand-response” design, in which a wind energy source and a PV system are connected to the supply grid via a common AC-to-DC converter. The AC-to-DC converter is in this case controlled by a signal from the supply grid.
US 2010/0198421 A1 has disclosed a connection system, in which a so-called “intelligent energy management system” controls the energy flow on the basis of, inter alia, energy prices. The system has a common AC-to-DC converter in combination with a multiport DC-to-DC converter. All of the DC devices are connected to a common DC bus via pulse-width-modulated semiconductor switches. One disadvantage with the described design is that the multiport DC-to-DC converter is a complex device and the DC devices need to be actuated in a complex manner in order to enable the connection to the common DC bus.